The Three Mile Island incident has raised concerns about proper alignment of valves in fluid systems used to mitigate the consequences of potential incidents at nuclear powered generating plants. In other words, the nuclear generating system has certain conduit and valve networks which are on a standby basis ready to perform a safety function when there is a plant malfunction. However, the present invention is not limited to monitoring standby systems. The characteristics of the system monitored exist in systems which are operative as well as in standby status.
Monitoring valve positions in conduit networks began with actual observation of the valve stem positions. This monitoring requires actual personal visits to each valve location. Alternatively, the position of valve stems can be sensed and electrically transmitted to a centralized control station. The present invention provides an alternate to these direct systems of checking the operability or continuity of these conduit networks and their included valves. A system utilizing acoustic energy is needed as an alternate or supplement to direct observation of the valve positions.